Airworthiness Directives; The Boeing Company Airplanes, 57078-57081 [2021-22251]

Download as PDF 57078 Proposed Rules Federal Register Vol. 86, No. 196 Thursday, October 14, 2021 This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2021–0828; Project Identifier AD–2021–00303–T] RIN 2120–AA64 Airworthiness Directives; The Boeing Company Airplanes Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: The FAA proposes to supersede Airworthiness Directive (AD) 2016–09–01, which applies to certain The Boeing Company Model 777–200 and –300 series airplanes. AD 2016–09– 01 requires repetitive inspections for cracking of the left-and right-side forward outer chords of the pivot bulkhead, and related investigative and corrective actions if necessary. AD 2016–09–01 also provides a modification of the pivot bulkhead, which terminates the repetitive inspections. Since the FAA issued AD 2016–09–01, it has received reports that cracking of the left- and right-side forward outer chords of the pivot bulkhead were found at earlier compliance times than those specified in AD 2016–09–01 and determined that the inspection areas must be expanded, and that additional inspections are needed in areas that were modified as specified in AD 2016–09–01. This proposed AD would retain certain requirements of AD 2016–09–01. This proposed AD would require doing repetitive detailed and high frequency eddy current (HFEC) inspections of the longeron fitting and, for certain airplanes, the bulkhead assembly structure, for any cracking and doing all applicable on-condition actions. The FAA is proposing this AD to address the unsafe condition on these products. lotter on DSK11XQN23PROD with PROPOSALS1 SUMMARY: VerDate Sep<11>2014 16:48 Oct 13, 2021 Jkt 256001 The FAA must receive comments on this proposed AD by November 29, 2021. ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments. • Fax: 202–493–2251. • Mail: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE, Washington, DC 20590. • Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this NPRM, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110–SK57, Seal Beach, CA 90740–5600; telephone 562–797–1717; internet https://www.myboeingfleet. com. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206–231–3195. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA–2021–0828. DATES: Examining the AD Docket You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA–2021–0828; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, any comments received, and other information. The street address for Docket Operations is listed above. FOR FURTHER INFORMATION CONTACT: Luis Cortez-Muniz, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: (206) 231–3958; email: Luis.A.CortezMuniz@faa.gov. SUPPLEMENTARY INFORMATION: Comments Invited The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send PO 00000 Frm 00001 Fmt 4702 Sfmt 4702 your comments to an address listed under ADDRESSES. Include ‘‘Docket No. FAA–2021–0828; Project Identifier AD– 2021–00303–T’’ at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend the proposal because of those comments. Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to https:// www.regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this proposed AD. Confidential Business Information CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as ‘‘PROPIN.’’ The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Luis Cortez-Muniz, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: (206) 231–3958; email: Luis.A.Cortez-Muniz@faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. Background The FAA issued AD 2016–09–01, Amendment 39–18499 (81 FR 26109, May 2, 2016) (AD 2016–09–01), for certain The Boeing Company Model 777–200 and –300 series airplanes. AD E:\FR\FM\14OCP1.SGM 14OCP1 Federal Register / Vol. 86, No. 196 / Thursday, October 14, 2021 / Proposed Rules 2016–09–01 was prompted by reports of fatigue cracking of the forward outer chord of the station (STA) 2370 pivot bulkhead. AD 2016–09–01 requires repetitive inspections for cracking of the left- and right-side forward outer chords of the pivot bulkhead, and related investigative and corrective actions if necessary. AD 2016–09–01 also provides a modification of the pivot bulkhead, which terminates the repetitive inspections. The agency issued AD 2016–09–01 to address fatigue cracking of the outer flanges of the left and right side forward outer chords of the STA 2370 pivot bulkhead, which could result in a severed forward outer chord and consequent loss of horizontal stabilizer control. Actions Since AD 2016–09–01 Was Issued Since the FAA issued AD 2016–09– 01, it has received reports that cracking of the left- and right-side forward outer chords of the pivot bulkhead were found at earlier compliance times than those specified in AD 2016–09–01 due to a combination of a stress concentration and high stress from complex loading at the structure of the transition radius of the forward outer chord flange. Boeing reopened the safety investigation and asked operators to gather additional data, which showed 32 airplanes with crack findings below the inspection threshold specified in AD 2016–09–01. Based on those findings, it has been determined that the compliance times must be reduced and the inspection areas for cracking must also be expanded to include the longeron fitting and, for post-repair and post-modification inspections, the bulkhead assembly structure. In addition, the FAA has determined that additional inspections are needed in areas that were modified as specified in AD 2016–09–01. FAA’s Determination The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design. Related Service Information Under 1 CFR Part 51 The FAA reviewed Boeing Alert Service Bulletin 777–53A0075, Revision 2, dated February 22, 2021. This service information specifies procedures for, depending on configuration, doing repetitive detailed and HFEC inspections of the STA 2370 pivot bulkhead forward outer chord and the longeron fitting for any cracking; doing repetitive post-repair inspections of the pivot bulkhead forward outer chord, longeron fitting, and bulkhead assembly structure for any cracking; doing repetitive post-modification inspections of the pivot bulkhead forward outer chord, longeron fitting, and bulkhead assembly structure for any cracking; and doing all applicable on-condition actions. On-condition actions include modifying the left and right forward outer chords and upper splice angles, and repair. This service information is reasonably available because the interested parties 57079 have access to it through their normal course of business or by the means identified in the ADDRESSES section. Proposed AD Requirements in This NPRM Although this proposed AD does not explicitly restate the requirements of AD 2016–09–01, this proposed AD would retain certain of the requirements of AD 2016–09–01. Those requirements are referenced in the service information identified previously, which, in turn, is referenced in paragraph (g) of this proposed AD. This proposed AD would reduce the compliance times for the inspections, add new inspection areas for any cracking, and add repetitive post-modification inspections. This proposed AD would also require accomplishment of the actions identified as ‘‘RC’’ (required for compliance) in the Accomplishment Instructions of Boeing Alert Service Bulletin 777–53A0075, Revision 2, dated February 22, 2021, described previously. For information on the procedures and compliance times, see this service information at https:// www.regulations.gov by searching for and locating Docket No. FAA–2021– 0828. Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 63 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: ESTIMATED COSTS Action Labor cost Detailed and HFEC inspections of the longeron fitting and pivot bulkhead forward chord. Post-repair inspections ............ Up to 15 work-hours × $85 per hour = Up to $1,275 per inspection cycle. $0 Up to $1,275 per inspection cycle. Up to $80,325 per inspection cycle. Up to 13 work-hours × $85 per hour = Up to $1,105 per inspection cycle. 18 work-hours × $85 per hour = $1,530 per inspection cycle. 0 Up to $1,105 per inspection cycle. Up to $69,615 per inspection cycle. 0 $1,530 per inspection cycle .... $96,390 per inspection cycle. Post-modification inspections .. lotter on DSK11XQN23PROD with PROPOSALS1 The FAA estimates the following costs to do any necessary modifications that would be required based on the Parts cost Cost per product results of the proposed inspection. The FAA has no way of determining the Cost on U.S. operators number of aircraft that might need this modification: ON-CONDITION COSTS Action Labor cost Modification .................................... Up to 137 work-hours × $85 per hour = Up to $11,645 ....................... VerDate Sep<11>2014 16:48 Oct 13, 2021 Jkt 256001 PO 00000 Frm 00002 Fmt 4702 Sfmt 4702 Parts cost E:\FR\FM\14OCP1.SGM 14OCP1 $34,086 Cost per product Up to $45,731. 57080 Federal Register / Vol. 86, No. 196 / Thursday, October 14, 2021 / Proposed Rules The FAA has received no definitive data on which to base the cost estimates for the repairs specified in this proposed AD. The FAA has included all known costs in its cost estimate. According to the manufacturer, however, all of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators. Authority for This Rulemaking Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency’s authority. The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings lotter on DSK11XQN23PROD with PROPOSALS1 The FAA has determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. For the reasons discussed above, I certify that the proposed regulation: (1) Is not a ‘‘significant regulatory action’’ under Executive Order 12866, (2) Would not affect intrastate aviation in Alaska, and (3) Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, VerDate Sep<11>2014 16:48 Oct 13, 2021 Jkt 256001 the FAA proposes to amend 14 CFR part 39 as follows: PART 39—AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: ■ Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by: a. Removing Airworthiness Directive (AD) 2016–09–01, Amendment 39– 18499 (81 FR 26109, May 2, 2016), and ■ b. Adding the following new AD: ■ ■ The Boeing Company: Docket No. FAA– 2021–0828; Project Identifier AD–2021– 00303–T. (a) Comments Due Date The FAA must receive comments on this airworthiness directive (AD) action by November 29, 2021. (b) Affected ADs This AD replaces AD 2016–09–01, Amendment 39–18499 (81 FR 26109, May 2, 2016) (AD 2016–09–01). (c) Applicability This AD applies to The Boeing Company Model 777–200 and –300 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 777–53A0075, Revision 2, dated February 22, 2021. (d) Subject Air Transport Association (ATA) of America Code 53, Fuselage. (e) Unsafe Condition This AD was prompted by reports of fatigue cracking of the forward outer chord of the station (STA) 2370 pivot bulkhead, and the determination that the compliance times need to be reduced, post-modification inspections must be done, and the inspections areas need to be expanded due to additional cracking found prior to the inspection times required by AD 2016–09– 01. The FAA is issuing this AD to address fatigue cracking of the outer flanges of the left and right side forward outer chords of the STA 2370 pivot bulkhead, which could result in a severed forward outer chord and consequent loss of horizontal stabilizer control. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions Except as specified by paragraph (h) of this AD: At the applicable times specified in paragraph 1.E., ‘‘Compliance,’’ of Boeing Alert Service Bulletin 777–53A0075, Revision 2, dated February 22, 2021, do all applicable actions identified as ‘‘RC’’ (required for compliance) in, and in accordance with, the Accomplishment Instructions of Boeing Alert Service Bulletin 777–53A0075, Revision 2, dated February 22, 2021. PO 00000 Frm 00003 Fmt 4702 Sfmt 4702 (h) Exceptions to Service Information Specifications (1) Where the ‘‘Effectivity’’ paragraph and the Condition and Compliance Time columns of the tables in the ‘‘Compliance’’ paragraph of Boeing Alert Service Bulletin 777– 53A0075, Revision 2, dated February 22, 2021, use the phrase ‘‘the Revision 2 date of this Service Bulletin,’’ this AD requires using ‘‘the effective date of this AD.’’ (2) Where Boeing Alert Service Bulletin 777–53A0075, Revision 2, dated February 22, 2021, specifies contacting Boeing for repair instructions: This AD requires doing the repair using a method approved in accordance with the procedures specified in paragraph (i) of this AD. (i) Alternative Methods of Compliance (AMOCs) (1) The Manager, Seattle ACO Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or responsible Flight Standards Office, as appropriate. If sending information directly to the manager of the certification office, send it to the attention of the person identified in Related Information. Information may be emailed to: 9-ANMSeattle-ACO-AMOC-Requests@faa.gov. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office. (3) An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by The Boeing Company Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO Branch, FAA, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD. (4) Except as specified by paragraph (h) of this AD: For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (i)(4)(i) and (ii) of this AD apply. (i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or substep is labeled ‘‘RC Exempt,’’ then the RC requirement is removed from that step or substep. An AMOC is required for any deviations to RC steps, including substeps and identified figures. (ii) Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator’s maintenance or inspection program without obtaining approval of an AMOC, provided the RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. (j) Related Information (1) For more information about this AD, contact Luis Cortez-Muniz, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des E:\FR\FM\14OCP1.SGM 14OCP1 Federal Register / Vol. 86, No. 196 / Thursday, October 14, 2021 / Proposed Rules Moines, WA 98198; phone and fax: (206) 231–3958; email: Luis.A.Cortez-Muniz@ faa.gov. (2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110–SK57, Seal Beach, CA 90740–5600; telephone 562–797–1717; internet https:// www.myboeingfleet.com. You may view this referenced service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206–231–3195. Issued on September 16, 2021. Lance T. Gant, Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2021–22251 Filed 10–13–21; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2021–0794; Project Identifier AD–2021–00400–T] RIN 2120–AA64 Airworthiness Directives; The Boeing Company Airplanes Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 747–400, –400D, and –400F series airplanes. This proposed AD was prompted by reports of burned Boeing Material Specification (BMS) 8–39 urethane foam, and a report from the airplane manufacturer that airplanes were assembled with seals throughout various areas of the airplane (including flight deck and cargo compartments) made of BMS 8–39 urethane foam, a material with fire-retardant properties that deteriorate with age. This proposed AD would require replacing the system tube/wire seals made of BMS 8–39 urethane foam in certain areas of the airplane. The FAA is proposing this AD to address the unsafe condition on these products. DATES: The FAA must receive comments on this proposed AD by November 29, 2021. ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: lotter on DSK11XQN23PROD with PROPOSALS1 SUMMARY: VerDate Sep<11>2014 16:48 Oct 13, 2021 Jkt 256001 • Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments. • Fax: 202–493–2251. • Mail: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE, Washington, DC 20590. • Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this NPRM, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110–SK57, Seal Beach, CA 90740–5600; telephone 562–797–1717; internet https://www.myboeingfleet. com. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206–231–3195. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA–2021–0794. Examining the AD Docket You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA–2021–0794; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, any comments received, and other information. The street address for Docket Operations is listed above. FOR FURTHER INFORMATION CONTACT: Julie Linn, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206–231–3684; email: julie.linn@faa.gov. SUPPLEMENTARY INFORMATION: Comments Invited The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under ADDRESSES. Include ‘‘Docket No. FAA–2021–0794; Project Identifier AD– 2021–00400–T’’ at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this proposal because of those comments. Except for Confidential Business Information (CBI) as described in the PO 00000 Frm 00004 Fmt 4702 Sfmt 4702 57081 following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to https:// www.regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM. Confidential Business Information CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as ‘‘PROPIN.’’ The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Julie Linn, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206–231–3684; email: julie.linn@ faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. Background The FAA has received reports of burned BMS 8–39 urethane foam, and a report from the airplane manufacturer that airplanes were assembled with seals throughout various areas of the airplane (including flight deck and cargo compartments) made of BMS 8–39 urethane foam, a material with fireretardant properties that deteriorate with age. The fire retardants in BMS 8– 39 urethane foam are mixed into, but are not chemically connected with, the remaining components of the foam, which causes the fire retardants to have decreased fire resistance over time. The degraded material can be an unacceptable fuel source for a fire if exposed to an ignition source. This condition, if not addressed, could result in failure of the urethane seals to maintain sufficient Halon concentrations in the cargo compartments to extinguish or contain fire or smoke, and to prevent penetration of fire or smoke in areas of the airplane that are difficult to access E:\FR\FM\14OCP1.SGM 14OCP1

Agencies

[Federal Register Volume 86, Number 196 (Thursday, October 14, 2021)]
[Proposed Rules]
[Pages 57078-57081]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-22251]


========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================


Federal Register / Vol. 86, No. 196 / Thursday, October 14, 2021 / 
Proposed Rules

[[Page 57078]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0828; Project Identifier AD-2021-00303-T]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) 
2016-09-01, which applies to certain The Boeing Company Model 777-200 
and -300 series airplanes. AD 2016-09-01 requires repetitive 
inspections for cracking of the left-and right-side forward outer 
chords of the pivot bulkhead, and related investigative and corrective 
actions if necessary. AD 2016-09-01 also provides a modification of the 
pivot bulkhead, which terminates the repetitive inspections. Since the 
FAA issued AD 2016-09-01, it has received reports that cracking of the 
left- and right-side forward outer chords of the pivot bulkhead were 
found at earlier compliance times than those specified in AD 2016-09-01 
and determined that the inspection areas must be expanded, and that 
additional inspections are needed in areas that were modified as 
specified in AD 2016-09-01. This proposed AD would retain certain 
requirements of AD 2016-09-01. This proposed AD would require doing 
repetitive detailed and high frequency eddy current (HFEC) inspections 
of the longeron fitting and, for certain airplanes, the bulkhead 
assembly structure, for any cracking and doing all applicable on-
condition actions. The FAA is proposing this AD to address the unsafe 
condition on these products.

DATES: The FAA must receive comments on this proposed AD by November 
29, 2021.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact Boeing 
Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; 
telephone 562-797-1717; internet https://www.myboeingfleet.com. You may 
view this service information at the FAA, Airworthiness Products 
Section, Operational Safety Branch, 2200 South 216th St., Des Moines, 
WA. For information on the availability of this material at the FAA, 
call 206-231-3195. It is also available at https://www.regulations.gov 
by searching for and locating Docket No. FAA-2021-0828.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0828; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains this NPRM, any comments 
received, and other information. The street address for Docket 
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Luis Cortez-Muniz, Aerospace Engineer, 
Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: (206) 231-3958; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2021-0828; Project Identifier 
AD-2021-00303-T'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
the proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this proposed AD.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to Luis 
Cortez-Muniz, Aerospace Engineer, Airframe Section, FAA, Seattle ACO 
Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 
(206) 231-3958; email: [email protected]. Any commentary that 
the FAA receives which is not specifically designated as CBI will be 
placed in the public docket for this rulemaking.

Background

    The FAA issued AD 2016-09-01, Amendment 39-18499 (81 FR 26109, May 
2, 2016) (AD 2016-09-01), for certain The Boeing Company Model 777-200 
and -300 series airplanes. AD

[[Page 57079]]

2016-09-01 was prompted by reports of fatigue cracking of the forward 
outer chord of the station (STA) 2370 pivot bulkhead. AD 2016-09-01 
requires repetitive inspections for cracking of the left- and right-
side forward outer chords of the pivot bulkhead, and related 
investigative and corrective actions if necessary. AD 2016-09-01 also 
provides a modification of the pivot bulkhead, which terminates the 
repetitive inspections. The agency issued AD 2016-09-01 to address 
fatigue cracking of the outer flanges of the left and right side 
forward outer chords of the STA 2370 pivot bulkhead, which could result 
in a severed forward outer chord and consequent loss of horizontal 
stabilizer control.

Actions Since AD 2016-09-01 Was Issued

    Since the FAA issued AD 2016-09-01, it has received reports that 
cracking of the left- and right-side forward outer chords of the pivot 
bulkhead were found at earlier compliance times than those specified in 
AD 2016-09-01 due to a combination of a stress concentration and high 
stress from complex loading at the structure of the transition radius 
of the forward outer chord flange. Boeing reopened the safety 
investigation and asked operators to gather additional data, which 
showed 32 airplanes with crack findings below the inspection threshold 
specified in AD 2016-09-01. Based on those findings, it has been 
determined that the compliance times must be reduced and the inspection 
areas for cracking must also be expanded to include the longeron 
fitting and, for post-repair and post-modification inspections, the 
bulkhead assembly structure. In addition, the FAA has determined that 
additional inspections are needed in areas that were modified as 
specified in AD 2016-09-01.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Service Bulletin 777-53A0075, 
Revision 2, dated February 22, 2021. This service information specifies 
procedures for, depending on configuration, doing repetitive detailed 
and HFEC inspections of the STA 2370 pivot bulkhead forward outer chord 
and the longeron fitting for any cracking; doing repetitive post-repair 
inspections of the pivot bulkhead forward outer chord, longeron 
fitting, and bulkhead assembly structure for any cracking; doing 
repetitive post-modification inspections of the pivot bulkhead forward 
outer chord, longeron fitting, and bulkhead assembly structure for any 
cracking; and doing all applicable on-condition actions. On-condition 
actions include modifying the left and right forward outer chords and 
upper splice angles, and repair.
    This service information is reasonably available because the 
interested parties have access to it through their normal course of 
business or by the means identified in the ADDRESSES section.

Proposed AD Requirements in This NPRM

    Although this proposed AD does not explicitly restate the 
requirements of AD 2016-09-01, this proposed AD would retain certain of 
the requirements of AD 2016-09-01. Those requirements are referenced in 
the service information identified previously, which, in turn, is 
referenced in paragraph (g) of this proposed AD. This proposed AD would 
reduce the compliance times for the inspections, add new inspection 
areas for any cracking, and add repetitive post-modification 
inspections. This proposed AD would also require accomplishment of the 
actions identified as ``RC'' (required for compliance) in the 
Accomplishment Instructions of Boeing Alert Service Bulletin 777-
53A0075, Revision 2, dated February 22, 2021, described previously.
    For information on the procedures and compliance times, see this 
service information at https://www.regulations.gov by searching for and 
locating Docket No. FAA-2021-0828.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 63 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
              Action                    Labor cost        Parts cost    Cost per product          operators
----------------------------------------------------------------------------------------------------------------
Detailed and HFEC inspections of   Up to 15 work-hours            $0  Up to $1,275 per      Up to $80,325 per
 the longeron fitting and pivot     x $85 per hour = Up                inspection cycle.     inspection cycle.
 bulkhead forward chord.            to $1,275 per
                                    inspection cycle.
Post-repair inspections..........  Up to 13 work-hours             0  Up to $1,105 per      Up to $69,615 per
                                    x $85 per hour = Up                inspection cycle.     inspection cycle.
                                    to $1,105 per
                                    inspection cycle.
Post-modification inspections....  18 work-hours x $85             0  $1,530 per            $96,390 per
                                    per hour = $1,530                  inspection cycle.     inspection cycle.
                                    per inspection
                                    cycle.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
modifications that would be required based on the results of the 
proposed inspection. The FAA has no way of determining the number of 
aircraft that might need this modification:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                Action                        Labor cost           Parts cost           Cost per  product
----------------------------------------------------------------------------------------------------------------
Modification.........................  Up to 137 work-hours x           $34,086  Up to $45,731.
                                        $85 per hour = Up to
                                        $11,645.
----------------------------------------------------------------------------------------------------------------


[[Page 57080]]

    The FAA has received no definitive data on which to base the cost 
estimates for the repairs specified in this proposed AD.
    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, all of the costs of this 
proposed AD may be covered under warranty, thereby reducing the cost 
impact on affected operators.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, General requirements. 
Under that section, Congress charges the FAA with promoting safe flight 
of civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of that 
authority because it addresses an unsafe condition that is likely to 
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    The FAA has determined that this proposed AD would not have 
federalism implications under Executive Order 13132. This proposed AD 
would not have a substantial direct effect on the States, on the 
relationship between the national Government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.
    For the reasons discussed above, I certify that the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive (AD) 2016-09-01, Amendment 39-18499 
(81 FR 26109, May 2, 2016), and
0
b. Adding the following new AD:

The Boeing Company: Docket No. FAA-2021-0828; Project Identifier AD-
2021-00303-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by November 29, 2021.

(b) Affected ADs

    This AD replaces AD 2016-09-01, Amendment 39-18499 (81 FR 26109, 
May 2, 2016) (AD 2016-09-01).

(c) Applicability

    This AD applies to The Boeing Company Model 777-200 and -300 
series airplanes, certificated in any category, as identified in 
Boeing Alert Service Bulletin 777-53A0075, Revision 2, dated 
February 22, 2021.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of fatigue cracking of the 
forward outer chord of the station (STA) 2370 pivot bulkhead, and 
the determination that the compliance times need to be reduced, 
post-modification inspections must be done, and the inspections 
areas need to be expanded due to additional cracking found prior to 
the inspection times required by AD 2016-09-01. The FAA is issuing 
this AD to address fatigue cracking of the outer flanges of the left 
and right side forward outer chords of the STA 2370 pivot bulkhead, 
which could result in a severed forward outer chord and consequent 
loss of horizontal stabilizer control.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    Except as specified by paragraph (h) of this AD: At the 
applicable times specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 777-53A0075, Revision 2, dated 
February 22, 2021, do all applicable actions identified as ``RC'' 
(required for compliance) in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Service Bulletin 777-
53A0075, Revision 2, dated February 22, 2021.

(h) Exceptions to Service Information Specifications

    (1) Where the ``Effectivity'' paragraph and the Condition and 
Compliance Time columns of the tables in the ``Compliance'' 
paragraph of Boeing Alert Service Bulletin 777-53A0075, Revision 2, 
dated February 22, 2021, use the phrase ``the Revision 2 date of 
this Service Bulletin,'' this AD requires using ``the effective date 
of this AD.''
    (2) Where Boeing Alert Service Bulletin 777-53A0075, Revision 2, 
dated February 22, 2021, specifies contacting Boeing for repair 
instructions: This AD requires doing the repair using a method 
approved in accordance with the procedures specified in paragraph 
(i) of this AD.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO Branch, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request 
to your principal inspector or responsible Flight Standards Office, 
as appropriate. If sending information directly to the manager of 
the certification office, send it to the attention of the person 
identified in Related Information. Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the responsible Flight Standards Office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by The Boeing Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, Seattle 
ACO Branch, FAA, to make those findings. To be approved, the repair 
method, modification deviation, or alteration deviation must meet 
the certification basis of the airplane, and the approval must 
specifically refer to this AD.
    (4) Except as specified by paragraph (h) of this AD: For service 
information that contains steps that are labeled as Required for 
Compliance (RC), the provisions of paragraphs (i)(4)(i) and (ii) of 
this AD apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. If a step or substep is labeled ``RC Exempt,'' then the 
RC requirement is removed from that step or substep. An AMOC is 
required for any deviations to RC steps, including substeps and 
identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(j) Related Information

    (1) For more information about this AD, contact Luis Cortez-
Muniz, Aerospace Engineer, Airframe Section, FAA, Seattle ACO 
Branch, 2200 South 216th St., Des

[[Page 57081]]

Moines, WA 98198; phone and fax: (206) 231-3958; email: 
[email protected].
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Contractual & Data Services 
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone 562-797-1717; internet https://www.myboeingfleet.com. You may view this referenced service 
information at the FAA, Airworthiness Products Section, Operational 
Safety Branch, 2200 South 216th St., Des Moines, WA. For information 
on the availability of this material at the FAA, call 206-231-3195.

    Issued on September 16, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-22251 Filed 10-13-21; 8:45 am]
BILLING CODE 4910-13-P